User blog comment:PokeFreak117/Excitement/@comment-32680552-20180623212925/@comment-32358261-20180624231820

You can still use mega swampert and primal kyogre. Swampert is obtained through island scan (marshtomp evolve) and kyogre is in one of the ultra wormholes. If you can’t do that GTS. Offer an OU Pokémon for a weakfish legendary. Slowly scale upward to kyogre.

You might think oh they are generally post game things but you don’t really need to go through competitive strats and stuff until post game.